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October 15, 2009

Inside an Electric Power Usage Meter

at 11:09 am. Filed under Electronic Hacks


We have all seen these power meters on the outside of homes but have you ever seen inside? Popular Science gives us a sneak peek inside one of these Electric Power Usage Meters. Oddly there is no crazy voodoo electronics or mechanical parts in there. Now the question is, based on knowing exactly how it’s constructed how can it be defeated? Sure if you rip it out and plug it in upside down to let it run backwards but is there a working covert method of making it run slower or stop? There is this Plug and Save device that has lots of crazy claims, I haven’t seen anywhere that explains what kind of magic is in the box though. I don’t see how it could work, anyone care to enlighten us on how it could or couldn’t work? Not sure if this article is a plant but it looks convincing.


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20 Responses to “Inside an Electric Power Usage Meter”

  1. pault Says:

    they supposedly work by power factor correction
    Do Power Factor Correction Devices (KVAR) really save money?


  2. Odin84gk Says:

    People have tried all sorts of hacks to “save money”. You can do things like poke it with a q-tip (slow down the spinning), put a supermagnet somewhere, or just do the normal thing and jumper around the meter.

    No matter what you do, it will only work for a month or two. If they have a decent AMR (automatic meter reader) system like Aclara, it will be detected.

  3. askjacob Says:

    There used to be some NASTY hacks here in Australia which involved mucking up the PFC so bad that the meter would slow or run backwards. It involved sinking a lot of current into a grounded metal pole, and some other stuff too (a coil and cap).

    It appears as though it was an extremely dangerous practice, as it created a dangerous power gradient around the ground pole, as well as a high risk of the power ground being at a live potential.

    That and the fact it consumed a large amount of power to work – made it rather easy to detect.

    Even before fancy automated power tracking, they still had power profiles of consumers (so anything unusual would get investigated) as well as a basic method of seeing that more power was distributed than sold.

    I never even thought it would have been worth the risk (power was pretty cheap back in the 80’s) as it sounded so damn dangerous. I guess it may have been popular with the drug crop growers who were trying to hide their power consumption for lighting?

    In all, I enjoy having pretty clean and regular power – and so as a genuine member of society am happy to pay my share for what I use…


  4. The voice in your head Says:

    Yeah, I prefer to avoid risking my life, and actually reduce my power usage rather than try to lie about how much I’ve used. Using LED/CFL lights, turning things off when not needed, and keeping the fridge set “just high enough” go a long way.

  5. yzf600 Says:

    That Plug and Save site has all the hallmarks of a worthless product. They claim all kinds of info, but make you give them your email for info on how it works or where to get it. They also have nasty pop-ups (even with a pop-up blocker) that prevent you from navigating away from their page. The pop ups say: “Don’t leave, we have special offers for you, just give us your email”. Even the embedded video “proof” from a TV news station was cut short and you are directed to email them for more info.

    Stay away from it.

  6. Shadyman Says:

    From http://energystar.custhelp.com/cgi-bin/energystar.cfg/php/enduser/std_adp.php?p_faqid=4941:

    “First, residential customers are not charged for KVA-hour usage, but by kilowatt-hour usage. This means that any savings in energy demand will not directly result in lowering a residential user’s utility bill.”

    This is what made me call BS as soon as I watched the video. The product supposedly lowers the voltage your devices use. (IE, you could be getting 122 Volts, it’ll lower it to 120, and supply the rest as amperage since it can’t change how much power an appliance uses. Power = Current * Voltage.) As the article above points out, consumers are billed for kilowatt-hours, or kilowatts over time.

    You’re still paying for the same amount of power whether it’s at 120V AC and 1 Amp or 1V AC and 120 Amp.

  7. direct rigger Says:

    try this for size …. first shut your power off. second, locate your electric meter. third,
    this might suck but if you want to save you got to do this and by doing so might cost you a cut
    lock fee on your next bill but its just that once…cut the lock off your meter unless you can pull
    off your meter without cuting. fourth, pull the meter out of the box. look behind the meter and
    on the side ther will be a silver tab thats bent in place. remove the silver tab but dont throw
    away. fifth, once the silver tab is removed twist the glass cover from the meter. looking at the
    meter from the front view ther is a hole around the bottom left where you will see a screw like
    in it and a diagram above the hole says left slow, right fast with a screwdriver turn it the left
    to slow the meter down. once done replace everything the way you pulled it off and turn the power
    back on. once you turn it back on the meter will spin fast the first 3 – 5 seconds and it will
    spin slow. this shit works cuz i have done this to mine and lots of friends homes and apartments
    in my city. my light bill was around 400- 600 a month and now its 200 – 400 a month with everthing
    on in my house with the a/c full blast at 65 … its always cold in my house.

  8. vic Says:

    This kind of meters do not use fancy electronics but is built in a clever way such that it computes the integral of U*I*cos(phi) over time. Meaning, only active power is measured. Thus, if you need to power a light bulb the same power will be registered whatever power factor correction techniques you try to use. Not to mention power companies have a limit of how low your power factor can go (I think its 0.8), because causes losses in the lines, needs higher kVA-rated transformers to provide the same kW, needs to produce more power in the power plants, and generally costs them more.

    The “Plug and Save” device is a capacitive power factor corrector. Residential power meters do not measure power factor, so I was curious to know more about their claims and I actually went into the trouble to request info on their website (using a trash email naturally 😉 ). I first received an email informing me that “the price will probably go higher today so buy quickly” … pathetic attempt at provoking an impulsive purchase, and a link to the “strictly confidential” exclusive area :
    Noticed the “we’ve just emailed you to confirm your address” ? It’s a static web page. They have no intent to send any additional information. They also constantly make the confusion between power and current. This is just a vast joke (or scam).

  9. Michael Says:

    I haven’t bought this but their price did go up last month. I was going to buy but am enjoying their email course which pretty much explains away a lot of the claims you guys have made. Why would a company offer a money-back guarantee (via credit card and paypal) if their products didn’t work?

  10. vic Says:

    Michael, care to share with us what specific information this “email course” contains ? I’ve asked for it but I’ve received nothing so far.

  11. Michael Says:

    vic – maybe because you used a trash email address.

  12. Alan Parekh Says:

    Hi Vic,

    That exclusive area is very convincing with the video demo etc. But just like yzf600 mentioned the site is setup to be so spammy it looses any credibility that I feel like it may deserve.

    In that exclusive area they are trying to get you to purchase one right now by saying “Hurry, prices for our residential powersaver are likely to increase after Friday, October 16, 2009.”

    They are making you feel that you have magically stumbled on this system on the very day that the price is going to go up, how lucky for you. Have a look at the code behind the page that generates the date…

    // Get today’s current date.
    var now = new Date();
    // Array list of days.
    var days = new Array(‘Sunday’,’Monday’,’Tuesday’,’Wednesday’,’Thursday’,’Friday’,’Saturday’);
    // Array list of months.
    var months = new Array(‘January’,’February’,’March’,’April’,’May’,’June’,’July’,’August’,’September’,’October’,’November’,’December’);
    // Calculate the number of the current day in the week.
    var date = ((now.getDate()<10) ? “0” : “”)+ now.getDate();
    // Calculate four digit year.
    function fourdigits(number) {
    return (number < 1000) ? number + 1900 : number; } // Join it all together today = days[now.getDay()] + ", " + months[now.getMonth()] + " " + date + ", " + (fourdigits(now.getYear())) ; // Print out the data. document.write(today);

  13. Kim Says:

    I’m a power-saver user myself but yes you do need to be careful who you buy from. There’s some nasty products out there, especially $20 powersavers from China.

  14. vic Says:

    Michael, this is a trash address for spam but I can still read what’s in there.
    Alan, good call on the javascript … Actually, they changed the page just today, no more reference to a price increase or email documentation. It just says that “your discount coupon expires at the end of today”. The video is convincing until you realize that in AC, current and power do not always go hand in hand. Of course the average person does not know this. Also the wiring is hidden.

  15. Wbeaty Says:

    Power factor capacitors do save energy …but only for the power company. If customers are using inductive loads, then PF capacitors can slightly lower the current in the entire power grid. Unfortunately, the utility companies will only pass the savings along to large industrial users, never to individual homeowners. Therefore, “plug and save” can honestly state that their product saves energy. But they’re lying if they claim that the product ever pays for itself, or ever reduces your electric bill.

    Also, PF capacitors can only work if the value of capacitance is correct for the motors currently in operation. Also, they only work right if induction motors are running in your home. Whenever you’re using electric lights and heating, but no fridge/furnace/washer motors, then “plug and save” will make your power factor worse, and will lose money for the utility companies.

    Most modern scam companies have discovered an amazing trick: if they honor a money-back guarantee, then they’ll rake in more victims, even though lots of people get a refund. (Perhaps they’ll keep everyone confused by only giving refunds for half their victims.) Most customers are too embarrassed to admit they were taken in by a scam. Rather than returning the product, instead they’ll try to convince themselves that the device really works. And most people fall for scams because they say to themselves “if they give refunds, then it CAN’T be a scam.” Guess what: modern scammers usually give refunds, since they found that this increases their profits on average.

    There’s more odd psychology behind the “magic box” scam. If you buy a PFC, then you’ve got some serious emotional investment in having it work right. So you’ll help it along unconsciously. You’ll start turning off lights! You’ll only run the dryer for a full load. You’ll take shorter showers. Like magic your electric bill will be smaller. But it’s really just the childrens story of “stone soup,” and you can make perfectly good soup without needing any expensive magic stone.

  16. Jeff Says:

    I am an electrician and have seen alot of different things going on…the simplest was a couple of wires going from line slot to load slot cutting about 25% of the bill. I have also seen customers simply by an identical meter from a local distributor where they are meant for divided billing in larger office complexes…then they simply pull their meter and put the other in for a week…
    HOWEVER… the one that I cannot find… is the capacitor across the line slots…I cant pull the pic from my phone but, i got a call from a freind of a freind of a freind (you know how that is). He was moving and wanted this device on his new meter. Well he tried to remove it himself with a bad result. The installer actually solder the leads onto the line side and when he cut 1 wire away… the unit slid right, phase to phase and melted some pieces and parts. I closed it up and gave him someone else to call. However, i have been looking for this application and cannot find it.
    Anyone hear of it?

  17. Green Says:

    Back in June, 2010, I bought a Power Saver from eBay and installed it myself. I moved into the house in June ’08, and we didn’t keep the electric bills from that year, but I tried to compare with our ’09 bills. Problem is that ’09 was a funky summer; lots of rain and cooler temp. So, I can’t say if I saved any money. We run our fan 24/7 and the temp set to 75 summer/72 winter, living in the middle of Arkansas. My bill has never run over $180/mo with a 2400 sq ft house. For what it’s worth.

  18. Tom Green Says:


  19. Kari Rastas Says:

    Power should have been free for the whole world way back in Nikola Teslas days, he had discovered the secrets of cosmic energy. The same as John Henry Moray did, both these men were basically told their is no money in free energy. Morays device was destroyed and lived his life in constant fear of assassination and carried a gun every where he went. I hate these power companies they are just greedy pigs, I wish everyone would rip them off, then maybe they will get the message that we know. This free energy debacle has been opposed for a long time. I have built 3 free energy devices that produce usable power. But I have found no government is interested in free energy because they make so much money from taxes on selling power, why would they want to loose trillions in income because someone like me can produce energy for free. You are all sheep following the rest, I will never pay for power again of this I am certain.

  20. Tony Says:

    Lay off the weed for a while, “rastas”.

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